Austrolebias adloffi (Ahl, 1922)

Volcan, Matheus Vieira, Barbosa, Crislaine, Robe, Lizandra Jaqueline & Lanés, Luis Esteban Krause, 2021, Molecular phylogeny of the Austrolebias adloffi group (Cyprinodontiformes Rivulidae), with description of two new endangered and highly endemic species of annual killifishes from the Laguna dos Patos system, southern Brazil, Zootaxa 4965 (1), pp. 87-113 : 106-107

Identification key for species of the Austrolebias adloffi species group

1a. Black blotches absent on the posterior portion of the caudal peduncle in females................................... 2

1b. Pair of black blotches vertically arranged on the posterior portion of the caudal peduncle in females.................... 4

2a. Males with overall colour pattern dark brown to black, with light narrow yellow or pale greenish yellow vertical bars...... 3

2b. Males with overall colour pattern light brown to dark brown, with dark gray, narrow vertical bars, bars becoming gradually shorter and fainter towards caudal peduncle................................................. Austrolebias bagual (middle Rio Camaquã basin, Brazil)

3a. Dorsal-fin origin slightly anterior to anal-fin origin in males; pectoral fin with a black stripe on ventral margin of pectoral fin in males; 25–31 preopercular plus mandibular neuromasts series................................ Austrolebias arachan (Upper Rio Jaguarão and upper Rio Negro basins, Brazil and Uruguay)

3b. Dorsal-fin origin slightly posterior to anal-fin origin in males; no black stripe on pectoral fin in males; 39–40 preopercular plus mandibular neuromasts series............................................................. Austrolebias viarius (Coastal river basins of southeastern Uruguay)

4a. Urogenital papilla attached to anal fin in males.............................................................. 5

4b. Urogenital papilla free from the anal fin in males............................................................ 6

5a. Transverse row of small spots on the middle portion of the dorsal fin in males; unpaired fins with a single row of light blue spots on their basal portion in males, preopercular and mandibular series of neuromasts united; dorsal-fin origin posterior to anal-fin origin in males..................................................................... Austrolebias pelotapes (Floodplains of lower Rio Pelotas basin and Arroio Santa Barbara basin, Brazil)

5b. Transverse row of small spots on the middle portion of the dorsal fin in males absent; anal and dorsal fins with wide black or dark gray bars at basal portion and caudal fin without bars or spots in males, preopercular and mandibular series of neuromasts separated; dorsal-fin origin anterior to anal-fin origin in males.................................. Austrolebias cheffei (Floodplains of lower Rio Camaquã basin, Brazil)

6a. Black blotch on the distal portion of the last anal and dorsal fin rays in males...................................... 7

6b. Black blotch on the distal portion of the last anal and dorsal fin rays absent...................................... 11

7a. Caudal fin with dots or spots on fin base................................................................... 8

7b. Dots or spots absent on caudal fin base................................................................... 10

8a. Dorsal fin origin anterior to anal-fin origin in both males and females...................... Austrolebias nigrofasciatus (São Gonçalo channel and floodplains of lower Rio Pelotas, Rio Piratini and Arroio Padre Doutor basins, Brazil)

8b. Dorsal fin origin posterior to anal fin origin in both males and females........................................... 9

9a. Transverse row of small spots on the middle portion of the dorsal fin in males absent; caudal peduncle alternating dark gray and light blue bars, dark gray bars slightly wider, equal or narrower than light blue bars............... Austrolebias nachtigalli (Floodplains of lower Arroio Grande and Arroio Juncal basin, Brazil)

9b. Transverse row of small spots on the middle portion of the dorsal fin in males; caudal peduncle in males predominantly dark brownish gray or dark gray to black, with narrow vertical light blue zones....................... Austrolebias pongondo (São Gonçalo channel and floodplains of mouth of Laguna dos Patos, Brazil)

10a. Dorsal fin yellowish green with light yellow or light bluish bars forming small triangles; dorsal fin base length 35.7–41.8 % SL in males......................................................................... Austrolebias lourenciano (Floodplains of middle-lower Arroio Pinto, Arroio São Lourenço basin, Brazil)

10b. Dorsal fin dark gray with yellowish light blue stripes; dorsal-fin base length 34.2–34.9 % SL in males...................................................................................................... Austrolebias reicherti (Drainage of Lagoa Mirim basin and floodplains of Rio Taquarí and rio Jaguarão basins, Uruguay)

11a. White yellow dots absent in dorsal and anal-fin bases........................................................ 12

11b. Dorsal and anal-fin bases with white yellow dots............................................ Austrolebias charrua (Coastal drainages of Lagoa Mirim basin, Brazil and Uruguay)

12a. All flank bars narrower than light interspace in males.......................................... Austrolebias adloffi (Rio Guaíba basin, Brazil)

12b. Dark bars on flank wider than light interspace.............................................. Austrolebias minuano (Coastal drainages of Laguna dos Patos basin, Brazil)